[技术]Arizona眼睛模型 [复制链接]

简介 &B8x0 yi  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 <qoc)p=__  
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模型 4J9Y  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 %7[d5[U~ZA  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. O~Jf"Ht  
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光源 " u]X/ {L  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 NHdNCHhA>-  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 =?M{B1;H  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 pcQzvLk  
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视网膜的散射 IYr4  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 sEb*GF*.V  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 Urm(A9|N  
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脚本 a{I(Qh!}  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： + VhD]!  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。
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余下的脚本计算与屈光度有关的所有参数。 s=&x%0f%  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 lt C  
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脚本代码 $Ehe8,=fj  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. CVgVyy^  
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Dim entity As T_ENTITY G
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Dim op As T_OPERATION @ojV8  
Dim mat As T_MODELMATERIAL T;Ra/H
 
Dim A As Double PAjH*5IA  
Dim pupilDiam As Double ,h9N,bIQg  
Dim eID As Long U'xmn$O  
Dim parID As Long qAVZ&:#  
Dim count As Integer pTcN8E&Unz  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double \4hB1-
 
Dim tlens As Double, nlens As Double s+]6X*)  
Dim curv As Double, conic As Double lDtl6r/  
Dim ok As Long &Ht5!zuW,  
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Sub Main ?wj1t!83  
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    '用户输入对话框 AI*1kxR  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 uRRp8hht  
        TextBox 220,21,40,21,.TextBox1 'default: 0 UV)!zgP  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 X2C&q$8  
        OKButton 40,91,90,21 @O&;%IZMY  
        CancelButton 190,91,90,21 2)R*d  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 05[k@f$n  
        TextBox 220,49,40,21,.TextBox2 'default: 4 /c52w"WW  
    End Dialog ]n&Eb88  
    Dim dlg As UserDialog >}!})]Xw9  
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    ok = Dialog (dlg) GPU,.s"&(  
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    If ok=0 Then    'cancel button was pressed  ood,k{  
        Print "Execution cancelled." [f@[gE  
        End #BwkbOgr  
    End If UZ 6:vmcT  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ^@A
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    If dlg.TextBox1 = "" Then U=\!`_f':  
        A = 0           'Default accommodation  C\5"Kb  
    Else 2VA mL7)  
        A = CDbl(dlg.TextBox1) CUZ ;<Pn  
    End If #TKByOcD2!  
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    If dlg.TextBox2 = "" Then f
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        pupilDiam = 4   'Default pupil diameter +G?nmXG[vj  
    Else v?qU/  
        pupilDiam = CDbl(dlg.TextBox2) 5"I8ric  
    End If 0fQMOTpOp  
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    Print " " Zdll}n
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    Print "Accommodation = " & A & " Diopters" qK12:  
    Print "Pupil Diameter = " & pupilDiam & " mm" QwgP+ M+  
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    ' Calculate new parameters with accommodation gOKF%Ej31T  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness )l"py9
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Jde@Th  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens A1V^Gi@i  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens %cFqD &6  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens FJ(}@U}57  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Dt\rMSjZ9  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 4-veO3&.h  
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    'Adjust parameters to account for accommodation <WRrB `nO  
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    '************************************************************************* /D&7 \3}  
    'Aqueous thickness (Position of Lens) =& =#G3f  
    '************************************************************************* wwD?i.3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) X4Y!Z/b  
    GetCustomElement eID, entity nH7i)!cI~  
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    parID = FindFullName( "Geometry.Arizona Eye" ) s2ixiv=  
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    ' Delete any shift(s) in z '\I!RAZ  
    count = 0
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    While GetOperationCount(eID)>count R8![ $mkU  
        GetOperation eID, count, op TG@ W:>N(  
        If op.Type="ShiftZ" Then xY94v  
            DeleteOperation eID,count `M.\D  
            count=count-1 EX9os  
        End If 0s'H(qE,_  
        count=count+1 @Rp#*{  
    Wend /7[X_)OG  
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    'Set new shift in IFfB3{J  
    op.Type = "ShiftZ" 8JbN&C  
    op.val1 = taq 3C7}
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    op.parent = parID }{(J*T  
    AddOperation eID, op <Gkmk?x`A  
    Print "Set aqueous humor thickness = " & taq-0.55 mKN#dmw6  
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    '************************************************************************* !au%D?w  
    'Radius and conic constant of anterior lens 7r,h[9~e  
    '************************************************************************* Qq*Ks 5   
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) s%l`XW;v  
    GetConic eID, entity, curv, conic }Z Nyd  
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    SetConic eID, entity, 1/Rant, CCant moT*r?l  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant "{"745H5  
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    '************************************************************************* k1HVvMD<  
    'Radius and conic constant of posterior lens ,J)wn;@  
    '************************************************************************* q6a7o=BP]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) lbUUf}   
    GetConic eID, entity, curv, conic gOL-b9W  
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    SetConic eID, entity, 1/Rpost, CCpost ('Doy1L  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost KKJ)BG?qZ  
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    '*************************************************************************  "yA=Tw  
    'Lens thickness (Position of posterior lens surface) g;To}0H  
    '************************************************************************* rIJv(&l  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Wd<|DmSy  
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    ' Delete any z-shift(s) V4>qR{5  
    count = 0 %=EN 3>,  
    While GetOperationCount(eID)>count 1Q>D^yPI[  
        GetOperation eID, count, op 3L1MMUACL  
        If op.Type="ShiftZ" Then -jdhdh  
            DeleteOperation eID,count tX@G`Mr(  
            count=count-1 `<x((@#  
        End If ilr'<5rq  
        count=count+1 i}E&mv'  
    Wend b"7L ;J5|  
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    'Set new z-shift Wt 1]9{$  
    op.Type = "ShiftZ" z8-dntkf  
    op.val1 = tlens }$E341@  
    op.parent = parID '%y5Dh  
    AddOperation eID, op Gw1Rp  
    Print "Set lens thickness = " & tlens $3c9iVK~_  
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    '************************************************************************* EPu-oE=HW4  
    'Lens index of refraction ` 5lW  
    '************************************************************************* o<Y[GW1pg  
    eID = FindMaterial( "Lens" ) L=#nnj-  
    GetModelMaterial eID, mat c3]`W7E6L  
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    mat.Nd = nlens v{c,>]@
 
    SetModelMaterial eID, mat _CImf1  
    Print "Set lens index of refraction = " & nlens =%Z5"];  
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    '************************************************************************* jL]Y;T8  
    'Pupil diameter .4O
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    '************************************************************************* r~q3nIe/,  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 2PTAIm Rq  
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    'Adjust pupil diameter (trimming volume inner hole) }|u>b!7_.  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" +L U.QI'  
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    ' Adjust pupil location to just in front of the lens ;6AanwR6  
    parID = FindFullName( "Geometry.Arizona Eye" ) e]DuV)k&  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) G<:gNWXd\  
    count = 0 a>8&B  
    While GetOperationCount(eID)>count cf+EQY  
        GetOperation eID, count, op Gr8%%]1!0  
        If op.Type="ShiftZ" Then CAa&,ZR  
            DeleteOperation eID,count 5`\"UC7?%  
            count=count-1 =lZtI6tZ  
        End If $e
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        count=count+1 LTWiCI  
    Wend %n@ ^$&,&;  
    op.Type = "ShiftZ" E/@  
    op.val1 = taq-0.01 B]#^&89wG)  
    op.parent = parID
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    AddOperation eID, op ?XllPnuKt%  
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    Print "Set pupil diameter = " & pupilDiam S;iJQS   
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    'Update AZ Eye subassembly Description @fh:
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    eID = FindFullName( "Geometry.Arizona Eye" ) UZRN4tru6  
    GetEntity eID, entity 4Is Wp!`W  
    entity.Description = "Accommodation = " & A & "D" a&Z;$  
    SetEntity eID, entity Mi)h<lY  
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    Update x T1

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    Print "DONE!" 6Wk9"?+1  
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End Sub !S#K6:  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： J b?x-%Za  
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Accommodation = 4 Diopters Ejt?B')aB5  
Pupil Diameter = 4 mm "h7Np/ m3  
Set aqueous humor thickness = 2.81  {HbSty  
Set anterior lens radius = 10.4 and conic constant = -2.375869 $EG9V++b3  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 66{Dyn7J~  
Set lens thickness = 3.927 aNUMF  
Set lens index of refraction = 1.42672 5;@2SY7,  
Set pupil diameter = 4 ijACfl{!:t  
DONE! hdDL92JVg